Search⌘ K
AI Features

The Spectrum of the Unit Impulse

Explore the concept of the unit impulse and its spectrum through the Discrete Fourier Transform. Understand how a unit impulse in time corresponds to an all-ones sequence in frequency, and examine the effects of shifting the impulse on its DFT output. This lesson helps you grasp fundamental DFT properties relevant for digital signal processing.

Understanding the DFT starts with the spectrum of a unit impulse. This case gives us an interesting result, as we will now see.

The signal

A unit impulse is a signal that is 00 everywhere, except at time index 00 where its value is 11. In mathematical terms, we say:

δ[n]={1,n=00,n0\begin{equation*} \delta[n] = \left\{ \begin{array}{l} 1, \quad n = 0 \\ 0, \quad n \neq 0 \\ \end{array} \right. \end{equation*} ...